\begin{tikzpicture}[
    node distance = 2cm and 2cm,
    N/.style = {circle, draw, font=\Large, minimum size=1.1em},
    every edge/.style = {draw, -> , semithick, shorten >=2pt},
    every edge quotes/.style = {auto=right, inner sep=2pt}
    ]
    
    %第一个图
    \node[N] (2) at (0,0) {2};
    \node[N] (3) at ([xshift=1.7cm,yshift=1cm]2) {3};
    \node[N] (4) at ([xshift=1.7cm,yshift=-2.5em]2) [label=right:{-}] {4};
    \node[] (占位1) at ([xshift=-2em]2) {};
    
    \path (2) edge [->] node [below right] {b} (3)
    (3) edge [->] node [right] (e1) {$\varepsilon$} (4)
    (4) edge [->] node [above right] {c} (2)
    (4) edge [bend left] node [below] {$\varepsilon$} (2)
    (2) edge [bend left] node [above] (e2) {$\varepsilon$} (3)
    (占位1.west) edge [->] node [above] {a} (2.west);
    
    
    %第二个图b
    \node[N] (22) at ([xshift=13em]2) [label=right:{-}] {2};
    \node[] (占位2) at ([xshift=-2em]22) {};
    \path (22) edge [loop above] node (b) [above] {b} (22) %循环
    (22) edge [loop below] node (c) [below] {c} (22) %循环 下
    (占位2.west) edge [->] node [above] {a} (22.west);
    
    \node[shape=single arrow, fill=orange!40, minimum height=3em] at ([xshift=8em]2) {};
    
\end{tikzpicture}